What is Underground Water?

Everything on the earth, including water, is affected by the force of gravity. 
In trying to pull water down towards the center of the earth, gravity pulls water into the ground. As water meets soil and rock, some soils let water soak through them. 
They are called porous soils. Non-porous soils do not let water pass through.What happens when rain water soaks into the ground? 
Soil is usually porous. So are some kinds of rock. 
Other kinds of rock are non-porous. 
Some types of soil are barely porous. 
Gravity makes rain water soak into most soils and also into porous rock. Once the soil and rock have become full of water, they cannot soak up any more water. 
They let the water pass through until it reaches non-porous rock. 
Then it can go no farther. 
The water gathers in the spaces between the rocks as groundwater.
All over the world there are great stores of groundwater. 
This sometimes escapes through holes in the surface to make a spring. 
Or else we can dig a well to reach it.